Bond order of N-O bonds in nitrate ion is

Options

A. `1.0`
B. `1.25`
C. `1.33`
D. `1.50`

Explanation

To determine the bond order of N-O bonds in the nitrate ion (NO3^-), we can follow these steps:

### Step 1: Identify the structure of the nitrate ion
The nitrate ion (NO3^-) consists of one nitrogen atom bonded to three oxygen atoms. The nitrogen atom is at the center, and the three oxygen atoms are arranged around it.

### Step 2: Draw the resonance structures
The nitrate ion has multiple resonance structures. In one resonance structure, one of the N-O bonds is a double bond, while the other two are single bonds. In another resonance structure, the double bond shifts to a different N-O bond. This means that there are three resonance structures for the nitrate ion.

### Step 3: Count the total number of bonds
In each resonance structure, we can count the number of N-O bonds:
- Each resonance structure has 1 double bond and 2 single bonds.
- A double bond counts as 2 bonds, while a single bond counts as 1 bond.

Thus, for one resonance structure:
- Total bonds = 1 (double bond) + 2 (single bonds) = 3 bonds.

Since there are three resonance structures, we can count the total number of bonds across all structures:
- Total number of bonds = 3 (from one structure) + 3 (from another structure) + 3 (from the third structure) = 9 bonds.

### Step 4: Calculate the bond order
The bond order is calculated using the formula:
\[ \text{Bond Order} = \frac{\text{Total number of bonds}}{\text{Total number of resonance structures}} \]
Here, we have:
- Total number of bonds = 4 (since each resonance structure contributes to the overall bond count).
- Total number of resonance structures = 3.

Thus, the bond order is:
\[ \text{Bond Order} = \frac{4}{3} \approx 1.33 \]

### Conclusion
The bond order of N-O bonds in the nitrate ion (NO3^-) is approximately 1.33.

---